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United States Patent |
5,666,848
|
Burns
|
September 16, 1997
|
Device for cutting and crimping pipes or tubes
Abstract
A crimping and cutting device for use on pipes comprises a frame (1 )
provided at one end with an anvil (4) to locate a pipe (P) during a
crimping and cutting operation. The device includes a crimping head (18)
and a cutting blade (28) which are movable towards the anvil (4) by,
respectively, first and second hydraulic actuators (11, 13). The two
actuators are mounted coaxially on the frame (1), with the first actuator
(11) being operatively connected to the second actuator (13). In
operation, the first actuator (11) is operated to move the second actuator
(13) which, in turn, moves the crimping head (18) so as to compress the
pipe against the anvil (4). Then the second actuator (13) is operated to
move the cutting blade (28) through a passage (35) formed in the crimping
head (18) so that the blade cuts through the compressed region of the pipe
(P).
Inventors:
|
Burns; Kevin John (Cumbria, GB)
|
Assignee:
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British Nuclear Fuels plc (GB)
|
Appl. No.:
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481464 |
Filed:
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August 2, 1995 |
PCT Filed:
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November 4, 1994
|
PCT NO:
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PCT/GB94/02429
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371 Date:
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August 2, 1995
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102(e) Date:
|
August 2, 1995
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PCT PUB.NO.:
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WO95/13160 |
PCT PUB. Date:
|
May 18, 1995 |
Foreign Application Priority Data
Current U.S. Class: |
72/326; 72/370.23; 72/453.02; 72/453.16 |
Intern'l Class: |
B21D 028/20 |
Field of Search: |
72/325-328,294,367,453.16,453.07,453.02
29/890.14
|
References Cited
U.S. Patent Documents
4516593 | May., 1985 | Muto | 72/367.
|
4790168 | Dec., 1988 | Vonthien | 72/326.
|
Foreign Patent Documents |
25 45 200 | May., 1977 | DE.
| |
Primary Examiner: Crane; Daniel C.
Attorney, Agent or Firm: Nixon & Vanderhye, P.C.
Goverment Interests
This application is a 371 of PCT/GB94/02429, filed on Nov. 4, 1994.
Claims
I claim:
1. A device for crimping and cutting a tubular component, the device
comprising:
a frame,
means defined by the frame to provide an anvil for locating said tubular
component to be cut,
crimping means mounted on said frame, said crimping means having a passage
formed therein and being movable towards said anvil to produce a
compressed region in the tubular component, and
a cutting blade adapted for movement through said passage towards the anvil
so as to cut through the tubular component at said compressed region
wherein the crimping means is moved by operation of a first fluid-operated
actuator and the cutting blade is moved by operation of a second
fluid-operated actuator.
2. A device according to claim 1, wherein the crimping means and the
cutting blade are each movable towards the anvil along the same axis.
3. A device according to claim 1, wherein the first actuator and the second
actuator are arranged coaxially on the frame.
4. A device according to claim 1, wherein the said second actuator is
mounted between the first actuator and the anvil, the second actuator
being operatively connected to the crimping means and the first actuator
being operatively connected to the second actuator, whereby operation of
the first actuator causes the second actuator to move the crimping means
towards the anvil.
5. A device according to claim 4, wherein the second actuator comprises a
fluid-actuated piston operatively connected to the cutting blade.
6. A device according to claim 1, wherein the crimping means comprises a
generally cylindrical body having an end surface facing the anvil the
passage comprising a diametral rectangular slot extending into the
crimping means from said end surface.
7. A device according to claim 6, wherein the passage opens into a recess
formed within the crimping means, the device further comprising blade
fixture means to provide a connection between the piston of said second
actuator and the cutting blade, the recess serving as a guideway for said
blade fixture means.
8. A device according to claim 1, wherein the anvil comprises two
substantially parallel web portions separated by channel means, the
arrangement being such that said channel means receives the cutting blade
when said blade cuts through the pipe (P).
9. A device according to claim 1, wherein the frame comprises a generally
tubular body portion each of said first and second actuators being
arranged one behind the other within said body portion.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to devices for cutting pipes or tubes, particularly,
but not exclusively, pipes or tubes which have been used to convey
hazardous material.
2. Discussion of Prior Art
When dismantling pipework which has been used to convey hazardous material,
such as radioactive fluids used in the nuclear industry, it is desirable
to put each pipe so that the two ends of the cut pipe are closed. This
prevents the escape of any harmful contaminants that may be contained in
the pipe.
It is known to sever pipes by means of a hydraulically-powered cutting tool
which is provided with a crimping attachment designed to compress the pipe
at the region to be cut. After compressing the pipe, the crimping
attachment is removed and replaced by a cutting blade. The cutting blade
is then operated to cut through the compressed region, leaving sealed pipe
ends on either side of the cut to prevent the escape of contaminants.
A disadvantage with this known pipe cutting tool is the necessity to remove
the crimping attachment and replace it with the cutting blade. This is
particularly disadvantageous when cutting pipes in hazardous environments,
such as a radioactive environment found in the nuclear industry, where it
is necessary for the operative to wear protective clothing. During the
exchange of the crimping attachment and cutting blade it is possible that
one of these items could damage the protective clothing. It will be
apparent that the leakage of harmful substances through the damaged
clothing causes a threat to the health of the operative. Therefore, in
addition to being a time consuming operation, the requirement to exchange
the crimping attachment and cutting blade is very undesirable from a
safety aspect.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a pipe crimping and cutting
device which overcomes the aforementioned disadvantage.
According to the invention there is provided a device for crimping and
cutting a pipe or similar component, the device comprising a frame, means
defined by the frame to provide an anvil for locating a pipe to be cut,
crimping means mounted on said frame, said crimping means having a passage
formed therein and being movable towards said anvil to produce a
compressed region in a pipe located by the anvil, and a cutting blade
adapted for movement through said passage towards the anvil so as to cut
through the pipe at said compressed region.
Preferably, the crimping means and the cutting blade are each movable
towards the anvil along the same axis.
The crimping means may be moved by operation of a first fluid-operated
actuator and the cutting blade is moved by operation of a second
fluid-operated actuator.
Advantageously, the first actuator and the second actuator are arranged
coaxially on the frame.
Preferably, the second actuator is mounted between the first actuator and
the anvil, the second actuator being operatively connected to the crimping
means and the first actuator being operatively connected to the second
actuator, whereby operation of the first actuator causes the second
actuator to move the crimping means towards the anvil.
In a preferred embodiment the second actuator comprises a fluid-actuated
piston operatively connected to the cutting blade.
The crimping means may comprise a generally cylindrical body having an end
surface facing the anvil, the passage comprising a diametral rectangular
slot extending into the crimping means from said end surface.
The passage preferably opens into a recess formed within the crimping
means, the device further comprising blade fixture means to provide a
connection between the piston of the second actuator and the cutting
blade, the recess serving as a guideway for the blade fixture means.
The anvil preferably comprises two substantially parallel web portions
separated by channel means, the arrangement being such that the channel
means receives the cutting blade when said blade cuts through the pipe.
The frame may comprise a generally tubular body portion, each of said first
and second actuators being arranged one behind the other within said body
portion.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention will now be described, by way of example, with
reference to the accompanying drawings, in which:
FIG. 1 is a part sectional front elevation of a crimping and cutting device
according to a first aspect of the invention,
FIG. 2 is a part sectional plan view of the crimping and cutting device
shown in FIG. 1, and
FIG. 3 is a part sectional isometric elevation of a crimping and cutting
device according to a second aspect of the invention.
DETAILED DISCUSSION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a crimping and cutting device for severing
pipes or tubes is shown and comprises a frame 1, which may be made from
titanium. The frame 1 has a handle portion 2 and a bed 3 which is formed
at one and into a fixed anvil 4. The anvil 4 has two hardened steel faces
5, 6 provided, respectively, on two parallel webs 7, 8 which are separated
by a deep channel 9.
At the end opposite to that of the anvil 4, the frame 1 is formed into an
annular boss 10 which has a screw-threaded bore to receive a
correspondingly screw-threaded portion of a first fluid-operated actuator
11. The actuator 11 includes a piston 12 which is connected to a second
fluid-operated actuator 13, which is co-axial with the first actuator 11,
by a connector 14 and a connector plate 15, attached to the actuator 13 by
screws 16. Preferably the actuators are hydraulic cylinder and piston
assemblies operated by oil.
The forward end of the actuator 13 is housed within an internal recess 17
formed in a crimping head 18. The crimping head is mounted in a guide 19
which has a guide plate 20 fixed by screws 21 to its underside on both
sides of the frame. In this region the frame bed 3 forms a guideway for
the guide 19 and the guide plates 20. At the forward end of the crimping
head 19 a reduced diameter spigot 22 is slidably arranged within a pipe
locator 23. A cut-out portion 24 formed in the pipe locator 23 has
converging sides extending from a front surface of the locator. A
compression spring 25 is housed within the space formed between the outer
surface of the spigot 22 and the inner surface of a recess 26 provided in
the crimping head 18.
A piston 27 contained in the second actuator 13 operates a pipe cutting
blade 29 of rectangular cross section and which has a forwardly projecting
tongue 29 and a rearwardly inclined cutting surface 30. The blade 28 is
connected to a blade fixture 31 which is attached to the piston 27 by
means of a connector 33. A recess 34 formed in the crimping head 18
defines a guideway for the blade fixture 31 and a rectangular passage 35,
extending into the recess from a front end surface of the crimping head,
serves as a guide for the blade 28. The passage 35 is disposed so as to
align with the anvil channel 9.
The crimping and cutting device operates as follows. A pipe or tube to be
cut, indicated by letter F, is placed in the device so that it is located
close to the faces 5, 6 of the anvil 4. A control button, not shown,
incorporated in the handle 2 is depressed so as to initiate the operation
of a hydraulic power pack of known type. Hydraulic oil from the power pack
is supplied to the first actuator 11 thereby causing forward movement of
the piston 12.
Movement of the piston 12 is transmitted through the connector plate 15 to
the second actuator 13 which, in turn pushes the crimping head 18 towards
the anvil faces 5, 6. Sliding movement of the crimping head 18 is guided
by the guide 19 and guide plates 20 which move along the guideway formed
on the bed 3 of the frame 1. Simultaneously, the pipe locator 23 is pushed
forwardly by the actuator 13 acting through the crimping head 18 and the
compression spring 25 until the pipe P locates in the cut-out portion 24.
Continued forward movement of the piston 12 causes the crimping head 18 to
slide through the pipe locator 23, thus compressing the spring 25. As a
result the crimping head 18 compresses and flattens the pipe against the
anvil faces 5, 6 so that a crimped region of about 5 cm length is formed
along the pipe.
A pressure relief mechanism on the power pack is then actuated so that oil
is bled to the second actuator 13, now stationary, thereby causing forward
movement of the piston 27. This movement is transmitted through the
connector 33 to the blade fixture 31 which moves forwardly along the
recess 34. This causes the blade 28 to move through the passage 35 which
guides the blade through the crimping head 18 so that the cutting surface
30 shears through the centre of the crimped region. During the cutting
stroke, the channel 9 formed in the anvil 4 receives the tongue 29 and the
cutting surface 30 of the blade 28.
On completion of the crimping and cutting operation a further control
button, not shown, on the handle 1 is depressed so that the actuators 11,
13 return to their original position by the action of springs incorporated
in the actuators.
A further embodiment of the invention is illustrated in FIG. 3, in which
the crimping and cutting device comprises a frame 36 formed from a
generally tubular body 37 and an anvil portion 4. Suitably, the tubular
body 37 may be made from aluminium and the anvil portion from titanium.
The anvil portion 4 has a boss 38 which is bored to provide a seating for
a reduced diameter spigot 39 formed at one end of the body 37. The anvil
portion 4 has two parallel webs 7, 8 provided, respectively, with two
hardened steel faces 5, 6 and separated by a deep channel 9.
At the rear end remote from the anvil portion 4 a first
hydraulically-operated actuator 11 is fixedly mounted in the body 37 and
has a piston operatively connected to a second hydraulically-operated
actuator 13. The second hydraulically-operated actuator 13 is slidably
mounted within the body 37. Hydraulic oil for operating the actuators 11,
13 is supplied through hoses 40, 41 respectively.
Slidably mounted within the front portion of the body 37 is a crimping head
18 which is connected to the forward end of the first actuator 13 by means
of an outwardly turned flange 42. Extending into a front end surface of
the crimping head 18 is a diametral rectangular passage 35 which is
disposed in alignment with the channel 9 formed in the anvil portion 4.
The passage 35 provides a guideway for the cutting blade 28 which is of
rectangular cross section and attached to a piston of the first actuator
13 by means of a blade fixture 43. As in the embodiment described
previously, the cutting blade 28 has a forwardly projecting tongue 29 and
a rearwardly inclined cutting surface 30. The passage 35 opens into a
recess 34 which seats on an annular spigot 44 projecting from the first
actuator 13. A handle 45 is attached to the tubular body 37 at
diametrically opposite sides thereof and a further handle 46 is provided
at the rear of the second actuator 11.
Incorporated in each of the handles 45, 46 are control buttons (not shown)
which are used to initiate, by means of an electronic control system (not
shown), the operation of the first and second actuators 11, 13. The
electronic control system is set so that the crimping force exerted on the
pipe by the crimping head 18 has the desired magnitude, depending on the
characteristics of the pipe being cut.
In operation, an operative grips a handle 45, 46 in each hand and
manoeuvres the crimping and cutting device so that the pipe or tube to be
cut is located close to the faces 5, 6 of the anvil portion 4. A control
button on one of the handles is operated so as to initiate operation of
the hydraulic power pack. Hydraulic oil from the power pack is transmitted
through the hose 40 to the first actuator 11 thereby causing forward
movement of the piston associated therewith.
Movement of this piston is transmitted to the second actuator 13 which
moves forwardly along the inside of the body 37. As the second actuator 13
moves forwardly, it pushes the crimping head 18 through the spigot 39
towards the anvil faces 5, 6. Thus the crimping head 18 compresses and
flattens the pipe against the anvil faces 5, 6 to form a crimped region
along the pipe.
A pressure relief mechanism on the power pack is then actuated so that oil
is supplied through the hose 41 to the second actuator 13. Thus, the
piston associated with the actuator 13, now stationary, is operated so as
to cause, by means of the blade fixture 43, forward movement of the
cutting blade 28 through the passage 35. The passage 35 guides the blade
28 through the crimping head 18 so that the inclined cutting surface 30
shears through the centre of the crimped region of the pipe. As the blade
28 cuts through the pipe the tongue 29 and the cutting surface 30 move
into the channel 9 formed in the anvil 4. After the pipe has been severed,
a further control button on one of the handles 45, 46 is depressed so that
the actuators 11, 13 are returned by their springs to their original
positions.
The crimping and cutting steps take place consecutively and are completed
within a time of 10-20 seconds, depending on the characteristics of the
pipe.
The resulting severed pipe has closed ends on either side of the cut
portion so that any harmful contaminants contained in the pipe are
prevented from escaping.
The device is capable of crimping and cutting stainless steel pipes having,
for example, nominal bores of up to one inch. It is constructed from
materials having weights which enable the device to be handled and
operated manually.
An advantage of the device is that pipes and tubes can be crimped and cut
without the necessity of interchanging the crimping head and cutting
blade, as is the case with known devices.
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